The NFL is in the midst of a watershed defensive revolution; one that is a decade (or, depending who you want to credit, decades) in the making.
Namely, he brought his wealth of coaching and football experience gleaned from his father, a renowned coach at Navy, Bill Parcells, his boss with the New York Giants, and as a coach himself, with Cleveland and, albeit briefly, the New York Jets.
But while he has also brought three Super Bowl trophies to New England, his lasting legacy throughout the league may be bringing the 3-4 back into style.
Belichick is hardly the first to utilize the system in the NFL—it first made its appearance in the NFL maybe 30 years before in Houston under Wade Phillips's father Bum Phillips* and, ironically, in New England—but he may be responsible for it finally sticking after it fell out of favor in the late 1980s and into the 1990s, even though the Steelers maintained it from 1982 onward and the Bills kept it continuously from 1979 through 2000.
*sidenote here, there's a bit of a controversy over who brought it to the league first. Bum Phillips is credited with it at Houston while other sources also credit Chuck Fairbanks in New England right around the same time. The 1972 Miami Dolphins also employed it, but I haven't seen them on film (besides the title game) so I don't know if it was their base or if it was just something they used when necessary.
As I'm sure you've read a thousand places before, the NFL is a copycat league. But it only copies what is deemed successful.
But the success of Belichick and the Steelers (especially under coordinator Dick LeBeau) in the last 10 years has cemented the 3-4's reputation around the league.
While the system popped up here and there through the 1970s and into the 1980s, its most successful early version was arguably that run by the Giants in the mid 1980s, leaning heavily on the singular talents of Lawrence Taylor.
(Edit note: I originally had the Steelers of the 1970s as the team using it long term with great success, but Pittsburgh didn't adopt the system until 1982 after the Steel Curtain retired. They are the longest running 3-4 team, however, and, despite what was incorrectly put here in an earlier version, have kept it, in a couple of different versions, since the 1982/1983 season.)
The new blocking rules instituted in 1978 allowed for offensive lineman be much more physical, extending their arms and opening their hands beyond the frames of their shoulders when pass blocking.
It allowed for bigger offensive linemen overall, since you didn't necessarily need the same lateral quickness that it took to block under the old rules.
While that change was big enough for the game, as offensive linemen got larger it simply became too hard for just three defensive linemen in that era to stuff the run when the offense turned upfield to plow the road.
With the advent of the 300-350 pound athletic monsters that populate 3-4 defensive lines these days, that's no longer really the case. But change was slow in coming.
Even Belichick, who began with the 3-4 in 2000, reverted to the 4-3 when the Patriots won their first Super Bowl. The Rocky II-esque Southpaw switch threw off opponents and Belichick stuck with it through the 2002 season.
But by 2003 Belichick saw a greater value in going back to his preferred system where he could take advantage of his personnel's unique abilities, as well as the market at large.
Trading for four-time Pro Bowler Ted Washington, he got the prototypical nose tackle that the 3-4 demands and, securing Roosevelt Colvin in free agency, he was able to pair two of the most versatile, athletic outside linebackers (Colvin and McGinest) to shave nearly a yard per carry from their run defense of the year before.
The rest—two Super Bowl victories and a very successful defense—is history.
The rest of the league took notice, and some other franchises followed the lead of teams like the Patriots, Ravens, and Steelers, copying their schemes and hiring their coaches.
But in the last two years, the 3-4 has exploded across the league and, in 2009, it's supposed (but certainly not definite) that 12 or 13 teams will employ it as their base formation.
Part of that is due to the defensive success of the Patriots and Steelers—the Ravens switched back to a 4-3 and 4-6 defensive package, but have waffled between the 3-4 and 4-3 the last few years—but part of it is the success of NFL offenses, like the Patriots since 2007, utilizing a "run-and-shoot" type gameplan.
James Lavin wrote in his book The Management Secrets of the New England Patriots that the original reason Belichick switched to the 3-4 was to combat the "spread" offense that teams were beginning to use more.
While the NFL "spread" is only a distant cousin to the type of offenses of the same name you see in college, the principle is similar: put as many receivers as you can manage on the field and beat defenders to the open space created before defenders can get to the quarterback.
In the NFL, that's easier said than done as the field stays the same size but the players, in general, just get bigger, more powerful, and faster.
Much, much faster.
The 3-4 is particularly suited to stopping the more wide open offenses, though, because it allows its primary rushers, its fast outside linebackers, to stand in a 2-point stance and either drop into coverage, rush the passer, or line up man-to-man and stay with a tight end.
The 4-3, with an extra large pass rusher playing nose-to-nose with an offensive lineman not available for pass coverage, hinders what a defense can do to confuse quarterbacks and makes it easier for the offense to find open seams and open receivers.
The 3-4 manages all that, however, without sacrificing much in run defense or the pass rush—as long as you have the correct personnel.
The Steelers have secured the servies of Casey Hampton for the last eight years and he's been among their most productive performers and a key player in their success the last few years.
Similarly, it was no happy accident that Belichick brought in Ted Washington when he returned to the 3-4, just as it's no accident that he drafted Vince Wilfork, another large run-stopping, gap-clogging force in the middle of the line.
What is an accident on Bill's part, however, may be the rebirth of the 3-4 across the league.
While speed-centric 4-3 defenses like the Tampa-2 system employed by the Buccaneers and Colts this decade have been able to shut down many passing attacks without giving up much in run support, they're still vulnerable without much bulk across the defense.
So when Belichick and Scott Pioli brought in Randy Moss and Wes Welker in 2007, the Patriots may have subsequently made their job finding defensive personnel much harder.
The Patriots were hardly the only team running a wide open offense in 2007, but their work (and vast success) primarily out of the shotgun with four receivers wide (they rarely, if ever, will employ a 5 WR look like a college spread) has almost necessitated the playing of faster, more agile, more versatile linebackers who can drop into coverage.
Basically, the NFL version of the "spread" offense's success has forced defenses to adapt by, as the Patriots did in 2003, adopting the 3-4.
This has a number of consequences.
First, let's look at the teams who will look to employ the 3-4 this season.
There were eight-to-nine teams that used it last year.
Baltimore used it somewhat, but they've been all over the place in that regard.
New England, Dallas, Cleveland, Miami, the New York Jets, Pittsburgh, San Diego, and San Francisco (only part-time, under Mike Nolan) employed the scheme, in some sort, for a large portion of their defensive snaps that weren't situational rushes.
This year Green Bay, Kansas City, and Denver are expected to join them. Cleveland will retain its 3-4 as it transfers from one former-Patriots-defensive-coordinator head coach in Romeo Crennel to another in Eric Mangini.
Replacing Mangini in New York is Rex Ryan, the Baltimore defensive coordinator who likes to employ a 3-4 as well and Baltimore could also employ the scheme again.
It's no accident, though, that eight of those teams are AFC teams. No team exclusively uses a "spread" or "run-and-shoot" offense" in the NFL, but plenty of teams often go to a four-receiver (or two TE) set and move to the shotgun or no-huddle to create mismatches on defense.
Many of the AFC passing attacks feature three-and-four receiver sets with a pass-catching tight end extensively, especially teams like New England (since 2007) and Indianapolis (since Manning).
If you're gameplanning for defensive playoff success in the AFC, those have to be your targets.
While a team may only be in their base defense 30-40 percent of the time, at most, being dominant on first and second down is always going to lead to dominance on third and fourth down, when defenses employ run blitzes or extra defensive backs depending on the situation.
With a 3-4 base defense, you simply are better suited to matching up with more receivers. With four linebackers who can all drop into coverage, the offense doesn't know where the rush is coming from before the ball is snapped.
Manning may gesture like he's dictating War and Peace in sign language pre-snap, but at most he's trying to read body language or key off of personnel and what he knows from film study—two outside linebackers standing up behind the line can always rush from both, all, or neither side anytime they wish and there's really no telling until they make their move.
Now, Manning is exceptional at film study, so he can create small advantages and at least believe he knows where the rush is coming from, but the extra man able to cover slot receivers or come after him still creates problems, even for a player of his caliber.
But the rebirth of the 3-4 perhaps comes down simply to a matter of finding the right people to fit your system.
When Belichick adopted the 3-4 in 2000 and again in 2003, it was an extremely valuable move for a franchise and coach that did not want to (or could not) lay out millions to get the most prized free agents.
The key positions in the 3-4—the pass-rushing outside linebackers, the mammoth nose tackle, and the huge, versatile defensive ends—all feature ideal body types that are poor fits for their respective positions in the 4-3.
All the defensive linemen in the 3-4 have to watch two gaps at once while confronting one, sometimes two, offensive linemen to defend the run. As a result, they have to be 290 pounds or bigger all across the line.
The nose tackle, in particular, has to be not only a mammoth (Ted Washington was 360-370 pounds and was considered ideal for his position), but has to take a mental and physical pounding.
There's a great run-down of the 3-4 here told to the Rocky Mountain News (R.I.P) by Joe Collier, who supposedly first taught Belichick the system. In that article, Collier explains the nose tackle is "the most important" player in the system.
Everyone would love to play quarterback, even with all the hits you have to take. You get all the plaudits, the praise, the money, the face-time.
The nose tackle instead gets to face double-teams all day, still has responsibility for two gaps, and must blow up huge fullbacks to get to the tailback on nearly every running play.
While he has two linebackers to help him in run support, they're usually watching for quick hitches over the middle and he's, generally, all by himself on the defensive line at the point of attack.
More from Collier in the article linked above:
"But that guy [the nose tackle] is the first guy you have to get," Collier said. "He has to be physically capable of playing the position and mentally tough enough to do it over the long haul. I used to ask [longtime Broncos nose tackle] Rubin Carter's son, Andre, all the time where he wanted to play in the NFL and he'd always say, 'Anywhere but nose tackle, because I saw how my dad walked around the house on Mondays.'
Basically, it's not a fun time. It takes a special type of football player to clog up the line in the 3-4.
The 3-4's biggest weakness, historically, has been its inability to stop runs up the gut. This is largely because the guys capable of playing the nose tackle position effectively are rare, rare finds.
It's just not easy to find a guy willing or able to do the work of two men.
They do exist, however.
But when you're the only 3-4 team in the business, getting that guy is a breeze, you can draft him later, pay him less, and compete with less teams for his services.
Washington was a four-time Pro Bowler when he came to the Patriots, but he wasn't really an ideal fit for the 4-3 and was considered a bit bigger than some would've liked for his position.
Even in the draft, the Patriots have often been able to stay pat at a low draft position and wait for their ideal guys to simply drop to them in the later rounds.
When there's 12 other teams looking to find the same generational guy, though, it becomes more difficult to secure the right kind of talent to support your system.
The same is true of all the other 3-4 specific guys who come out of college.
You've no doubt heard the term "tweener" and "hybrid" a lot in this past draft. It's largely because the league is nearly split down the middle between the two defensive bases.
Guys like Aaron Maybin, for instance, are prized assets whereas, a decade ago many teams might pass because size-wise, he's stuck between two positions.
Maybin, a DE in college, may have a hard time playing the position in the NFL because, even after putting on nearly 30 pounds before the combine he is still just 250 pounds.
Small for a defensive lineman, perhaps, but closer to ideal as a 3-4 outside linebacker.
With his exceptional first step, 4.59 speed (once he adjusted to being 25 pounds heavier) and nearly 40'' vertical leap, he has a real future as a pass-rushing OLB who can drop into coverage and stay with receivers.
It showed with his draft, where he was taken 11th overall by the Bills. The Bills will primarily use him as a speedy DE pass-rusher in the vein of Dwight Freeney (who is considered undersized at 268 pounds for the position, 15 pounds heavier than Maybin was at his Pro Day).
It's likely he's a situational rusher prospect who will make the switch to 3-4 OLB at his newfound size or continue to put on weight (he hasn't speculated as to his ideal weight, according to what I've seen and read) and stay as a 4-3 DE.
The same was true of the best nose tackle prospect in the draft, B.J. Raji. Despite being pegged with having a shorter wingspan than ideal, Raji was a defensive coordinator's dream player to build a 3-4 around.
Big, good mean streak, mentally and physically tough. Still, if you're drafting for a 4-3, a bigger-than-you-need nose tackle with questionable wingspan, no matter how tough he is, is likely not a first-round pick.
But with the Packers making the switch to the 3-4, they were lauded for picking the guy with the ninth pick. This isn't a dig at the Packers, they by far made the right move, but Raji is a guy who, in past years, likely would've fallen to later in the first round.
Having more teams defend from a 3-4 base also presents the problem, for a team like the Patriots, of holding on to your franchise players.
Vince Wilfork, for example, is expected to begin, officially, holding out of mandatory sessions (the OTAs he skipped thus far are "voluntary") this week.
(Update: he appeared at the first mandatory minicamp of the season this week, so if he is going to hold out, it likely won't be for awhile.)
Whereas in 2003 or 2004 the Patriots could have simply waited (and likely will anyway) or even let Wilfork hit free agency without having to pay him the money he's seeking (something in the range of $10 million per year, reportedly), now he's going to command a much higher price tag.
It's all simply a numbers game: there's just no shortage of teams now who will gladly shell out franchise money for a guy who, in the 3-4 more than any other scheme, is an absolutely essential player.
In the end, it's just another chapter in the long history of strategic shifts that the NFL has taken.
But it's a shift that will, at the very least, make it more difficult for teams like Pittsburgh and New England, who once held the monopoly on ideal 3-4 defenders, to succeed the way they have this past decade.